Further, recent changes to the World Health Organisation (WHO) guidelines have defined a class of hybrid RO-chRCC tumours defined as “other oncocytic/chromophobe RCC” for which MTOR or TSC1/2 mutations are frequently the primary driver, with suggestion that rapalogs may be an effective targeted treatment as in adult RCC patients with advanced disease [19–21]. Here, TSC1 is linked to neoplasm.